Molecular detection of toxoplasmosis in wild rats using loop-mediated isothermal amplification assay.

Background and Aim: Toxoplasmosis is caused by the parasite Toxoplasma gondii. Cats are the only known hosts that excrete resistant oocysts. Wild rats serve as crucial reservoirs and intermediate hosts for T. gondii's survival and dissemination. Consuming soil and water containing oocysts can lead to illness. This study aimed to estimate the prevalence of toxoplasmosis in wild rats through molecular detection as an indicator of environmental contamination in Surabaya. Materials and Methods: One hundred rats were collected from the three areas (housing, dense settlements, and traditional markets) and distributed into the five zones: West, East, Central, North, and South of Surabaya. Brain tissue samples were extracted using a Geneaid™ (New Taipei City, Taiwan) DNA isolation kit and analyzed through the loop-mediated isothermal amplification (LAMP) method. Results: The study analyzed brain tissue from 100 wild rats, consisting of 77 Rattus tanezumi and 33 Rattus norvegicus, displaying 30% LAMP positivity. The study revealed that 30% (30/100) of wild rats tested were infected with T. gondii. The molecular prevalence rate in male rats was 32.35% (22/68), compared to females with 25% (8/32). 41.9% of the housing population, 33.3% of traditional markets, and 22.6% of dense settlements had the highest molecular prevalence. The high positive molecular rate at the trapping site can be attributed to cats and dense populations. Conclusion: Thirty percentage wild rats were tested positive for toxoplasmosis in Surabaya, East Java, Indonesia using LAMP method. Implementing strict control and monitoring is crucial in preventing the transmission of diseases from wild rats to humans. It is necessary to carry out further research related to genetic analysis of T. gondii to determine the type of T. gondii that infects animals and humans in Surabaya through bioassay and molecular test.

Tissue cysts and serological detection toxoplasmosis among wild rats from Surabaya, East Java, Indonesia.

Background: The protozoan Toxoplasma gondii is the source of zoonosis toxoplasmosis and causes public health problems throughout the world. Environmental contamination by oocysts excreted by cats as definitive hosts affects the spread of this disease. Wild rats as rodents can be used as an indicator of environmental contamination by oocysts, considering that rats have a habit of living in dirty environments and can be infected by oocysts from the environment. Aim: This study aims to detect toxoplasmosis from tissue cysts and serological tests in wild rats as an indicator of environmental contamination in Surabaya. Methods: A total of 100 wild rats collected from Surabaya were collected in five areas (West, East, Central, North, and South of Surabaya) obtained from three trapping locations: housing, dense settlements, and markets. All samples were examined microscopically for parasitological tests through the brain tissue samples, and the serum was examined using the toxoplasma modified agglutination test to detect the presence of IgG and Immunoglobulin M (IgM). Results: This research used 100 wild rat samples, 77 Rattus tanezumi and 33 Rattus norvegicus, with evidence of 31% in serology and active infection with 19% tissue cyst. The results showed that the seroprevalence of T. gondii in wild rats was 31% (30% for IgG and 1% for IgM). Tissue cysts in the rat brain samples tested were 19% (19/100). The IgG prevalence rate in female rats was 25% (8/32), while for males, it was 32.3% (22/68). The highest seropositive IgG from densely populated settlements was 50%, markets were 25.8%, and housing was 12.1%. The highest seropositive IgM from densely populated settlements was 2.8%. Population density and the presence of cats are factors supporting the high seropositive rate at the trapping location. Conclusion: This study revealed that there has been toxoplasmosis contamination in Surabaya with evidence of 31% in serology and active infection with 19% tissue cyst. It is necessary for controlling with surveillance in cats to prevent transmission in humans.

Morphology and histology of paryphasmata and hemibaculum of Varanus salvator based on sexual maturity.

Background: Varanus salvator is one of the reptiles being hunted by human beings for several purposes, including traditional medicine. The studies about reproductive biology aspects were limited. Aim: This study aimed to determine the morphology, histology, and histometry of V. salvator paryphasmata and hemibaculum based on Snout-Vent Length (SVL) as an indicator of sexual maturity. Methods: This study examined 18 pairs of hemipenis of V. salvator with SVL more and less than 40 cm in equal number. Paryphasmata and hemibaculum parts were observed visually and micro-sliced, then stained with Hematoxylin-Eosin (HE). The histological observation was conducted under a 40×, 100×, and 400× magnification of a light microscope. The histometry of the paryphasmata was examined using 13 Megapixels Coolpad and OptiLab Plus for microscopic pictures. The chondrocyte cell area was measured using the Optilab Plus and Image Raster three applications. Results: The sizes of glans of hemipenis, paryphasmata, and hemibaculum increased according to the increasing of SVL. The average paryphasmata row number, epidermis, and loose connective tissue thickness were not significantly different (p > 0.05). However, dense connective tissue was thicker (p < 0.05), which corresponds to SVL. Hemibaculum was composed of fibrous and hyaline cartilage characterized by chondrocyte cells. The SVL also affects (p < 0.05) the ossification of hyaline in hemipenis, while the chondrocyte cell area followed the equation -1.87E7 + 7.09E5* SVL. Conclusion: The SVL size of V. salvator affects the paryphasmata, hemibaculum, thickness of dense connective tissue of paryphasmata, and the area of chondrocyte cells.